draco_myst
New member
I have a water chemistry question, and I was hoping someone could provide me with some guidance. I have always understood that the goal is to reduce nitrates and phosphates as much as possible in a reef aquarium, but I can't seem to keep the nitrates down.
System:
55 gallon tank (set up since August '06)
80 lbs live rock
25 lbs live sand
50 lbs crushed coral
500w Halide
220w PC (110w Actinic - always on, 110w 10K - off when halides on)
40 gallon sump (25 gallons of which is refugium)
50 lbs live sand
small skimmer
110w PC (55 10K & 55 Blue)
Parameters:
pH 8.2
salinity 1.023
temp 78 degF
Alkalinity 10 dkh
calcium 420
amonium/nitrite 0 ppm
phosphate 0 ppm
nitrate 20 ppm and climbing
The corals have all been growing well (zoos, mushrooms, SPS, LPS, xenia). They had been dull in color under the PC lights, but now are showing intense colors since we added the halides and put in new actinic bulbs. We try not to overfeed the fish or the corals (0-2 times per day), in fact our sand sifting starfish just died most likely from starvation. The orange diamond goby digs like crazy looking for food and the sand is very clean. The water looks clear as crystal, though removed water during water changes looks yellow. I've typically changed 15 gallons once a week, though last week I changed 40 gallons in an attempt to reduce the nitrates from 20 ppm. It only dropped to around 15. A week later it is back up to 20 again.
The alges in our tank grow very slowly (a small amount of hair alge in the main tank, the cheto in the refugium) except for the corraline (red and purple) which has been increasing on the live rock quite well. It is my understanding that green alges require both phosphates, and nitrates to grow. The fact that our phosphate level is near zero (due to RODI water use?) probably explains the slow growth. Here is the question . . . if nitrate export through cheto growth is desired, isn't SOME phosphate required? Am I not fighting a losing battle with the nirtates if the alge can't consume them due to a lack of phosphate? I know it sounds crazy to think about deliberately adding phosphate to the system, but it almost seems that that's what I would need to do to get the cheto to grow and thus reduce the nitrates. What do you guys think? Does the tank need more time to mature? (The majority of the live rock came out of a matured tank) Do we need more rock?
System:
55 gallon tank (set up since August '06)
80 lbs live rock
25 lbs live sand
50 lbs crushed coral
500w Halide
220w PC (110w Actinic - always on, 110w 10K - off when halides on)
40 gallon sump (25 gallons of which is refugium)
50 lbs live sand
small skimmer
110w PC (55 10K & 55 Blue)
Parameters:
pH 8.2
salinity 1.023
temp 78 degF
Alkalinity 10 dkh
calcium 420
amonium/nitrite 0 ppm
phosphate 0 ppm
nitrate 20 ppm and climbing
The corals have all been growing well (zoos, mushrooms, SPS, LPS, xenia). They had been dull in color under the PC lights, but now are showing intense colors since we added the halides and put in new actinic bulbs. We try not to overfeed the fish or the corals (0-2 times per day), in fact our sand sifting starfish just died most likely from starvation. The orange diamond goby digs like crazy looking for food and the sand is very clean. The water looks clear as crystal, though removed water during water changes looks yellow. I've typically changed 15 gallons once a week, though last week I changed 40 gallons in an attempt to reduce the nitrates from 20 ppm. It only dropped to around 15. A week later it is back up to 20 again.
The alges in our tank grow very slowly (a small amount of hair alge in the main tank, the cheto in the refugium) except for the corraline (red and purple) which has been increasing on the live rock quite well. It is my understanding that green alges require both phosphates, and nitrates to grow. The fact that our phosphate level is near zero (due to RODI water use?) probably explains the slow growth. Here is the question . . . if nitrate export through cheto growth is desired, isn't SOME phosphate required? Am I not fighting a losing battle with the nirtates if the alge can't consume them due to a lack of phosphate? I know it sounds crazy to think about deliberately adding phosphate to the system, but it almost seems that that's what I would need to do to get the cheto to grow and thus reduce the nitrates. What do you guys think? Does the tank need more time to mature? (The majority of the live rock came out of a matured tank) Do we need more rock?
